From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/mailbox/rockchip-mailbox.c | 241 +++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 drivers/mailbox/rockchip-mailbox.c (limited to 'drivers/mailbox/rockchip-mailbox.c') diff --git a/drivers/mailbox/rockchip-mailbox.c b/drivers/mailbox/rockchip-mailbox.c new file mode 100644 index 000000000..bc2f9dd79 --- /dev/null +++ b/drivers/mailbox/rockchip-mailbox.c @@ -0,0 +1,241 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define MAILBOX_A2B_INTEN 0x00 +#define MAILBOX_A2B_STATUS 0x04 +#define MAILBOX_A2B_CMD(x) (0x08 + (x) * 8) +#define MAILBOX_A2B_DAT(x) (0x0c + (x) * 8) + +#define MAILBOX_B2A_INTEN 0x28 +#define MAILBOX_B2A_STATUS 0x2C +#define MAILBOX_B2A_CMD(x) (0x30 + (x) * 8) +#define MAILBOX_B2A_DAT(x) (0x34 + (x) * 8) + +struct rockchip_mbox_msg { + u32 cmd; + int rx_size; +}; + +struct rockchip_mbox_data { + int num_chans; +}; + +struct rockchip_mbox_chan { + int idx; + int irq; + struct rockchip_mbox_msg *msg; + struct rockchip_mbox *mb; +}; + +struct rockchip_mbox { + struct mbox_controller mbox; + void __iomem *mbox_base; + + /* The maximum size of buf for each channel */ + u32 buf_size; + + struct rockchip_mbox_chan chans[]; +}; + +static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); + struct rockchip_mbox_msg *msg = data; + struct rockchip_mbox_chan *chans = mb->chans; + + if (!msg) + return -EINVAL; + + if (msg->rx_size > mb->buf_size) { + dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n", + mb->buf_size); + return -EINVAL; + } + + dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n", + chans->idx, msg->cmd); + + mb->chans[chans->idx].msg = msg; + + writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx)); + writel_relaxed(msg->rx_size, mb->mbox_base + + MAILBOX_A2B_DAT(chans->idx)); + + return 0; +} + +static int rockchip_mbox_startup(struct mbox_chan *chan) +{ + struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); + + /* Enable all B2A interrupts */ + writel_relaxed((1 << mb->mbox.num_chans) - 1, + mb->mbox_base + MAILBOX_B2A_INTEN); + + return 0; +} + +static void rockchip_mbox_shutdown(struct mbox_chan *chan) +{ + struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); + struct rockchip_mbox_chan *chans = mb->chans; + + /* Disable all B2A interrupts */ + writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN); + + mb->chans[chans->idx].msg = NULL; +} + +static const struct mbox_chan_ops rockchip_mbox_chan_ops = { + .send_data = rockchip_mbox_send_data, + .startup = rockchip_mbox_startup, + .shutdown = rockchip_mbox_shutdown, +}; + +static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id) +{ + int idx; + struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id; + u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS); + + for (idx = 0; idx < mb->mbox.num_chans; idx++) { + if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) { + /* Clear mbox interrupt */ + writel_relaxed(1 << idx, + mb->mbox_base + MAILBOX_B2A_STATUS); + return IRQ_WAKE_THREAD; + } + } + + return IRQ_NONE; +} + +static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id) +{ + int idx; + struct rockchip_mbox_msg *msg = NULL; + struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id; + + for (idx = 0; idx < mb->mbox.num_chans; idx++) { + if (irq != mb->chans[idx].irq) + continue; + + msg = mb->chans[idx].msg; + if (!msg) { + dev_err(mb->mbox.dev, + "Chan[%d]: B2A message is NULL\n", idx); + break; /* spurious */ + } + + mbox_chan_received_data(&mb->mbox.chans[idx], msg); + mb->chans[idx].msg = NULL; + + dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n", + idx, msg->cmd); + + break; + } + + return IRQ_HANDLED; +} + +static const struct rockchip_mbox_data rk3368_drv_data = { + .num_chans = 4, +}; + +static const struct of_device_id rockchip_mbox_of_match[] = { + { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data}, + { }, +}; +MODULE_DEVICE_TABLE(of, rockchip_mbox_of_match); + +static int rockchip_mbox_probe(struct platform_device *pdev) +{ + struct rockchip_mbox *mb; + const struct rockchip_mbox_data *drv_data; + struct resource *res; + struct clk *pclk; + int ret, irq, i; + + if (!pdev->dev.of_node) + return -ENODEV; + + drv_data = (const struct rockchip_mbox_data *) device_get_match_data(&pdev->dev); + + mb = devm_kzalloc(&pdev->dev, struct_size(mb, chans, drv_data->num_chans), GFP_KERNEL); + if (!mb) + return -ENOMEM; + + mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans, + sizeof(*mb->mbox.chans), GFP_KERNEL); + if (!mb->mbox.chans) + return -ENOMEM; + + platform_set_drvdata(pdev, mb); + + mb->mbox.dev = &pdev->dev; + mb->mbox.num_chans = drv_data->num_chans; + mb->mbox.ops = &rockchip_mbox_chan_ops; + mb->mbox.txdone_irq = true; + + mb->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); + if (IS_ERR(mb->mbox_base)) + return PTR_ERR(mb->mbox_base); + + /* Each channel has two buffers for A2B and B2A */ + mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2); + + pclk = devm_clk_get_enabled(&pdev->dev, "pclk_mailbox"); + if (IS_ERR(pclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(pclk), + "failed to get and enable pclk_mailbox clock\n"); + + for (i = 0; i < mb->mbox.num_chans; i++) { + irq = platform_get_irq(pdev, i); + if (irq < 0) + return irq; + + ret = devm_request_threaded_irq(&pdev->dev, irq, + rockchip_mbox_irq, + rockchip_mbox_isr, IRQF_ONESHOT, + dev_name(&pdev->dev), mb); + if (ret < 0) + return ret; + + mb->chans[i].idx = i; + mb->chans[i].irq = irq; + mb->chans[i].mb = mb; + mb->chans[i].msg = NULL; + } + + ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox); + if (ret < 0) + dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret); + + return ret; +} + +static struct platform_driver rockchip_mbox_driver = { + .probe = rockchip_mbox_probe, + .driver = { + .name = "rockchip-mailbox", + .of_match_table = rockchip_mbox_of_match, + }, +}; + +module_platform_driver(rockchip_mbox_driver); + +MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU"); +MODULE_AUTHOR("Addy Ke "); +MODULE_AUTHOR("Caesar Wang "); -- cgit v1.3.1